1. Field of the Invention
The present invention relates to a construction machine wherein a tank accommodating space with a fuel tank accommodated therein is covered with a bonnet from above and wherein an operator's seat is provided on the bonnet.
2. Description of the Related Art
With a small-sized hydraulic excavator (compact excavator) as an example, which is a suitable example of the present invention, a description will be given below about the background art.
In a compact excavator, as shown in FIGS. 6 and 7, an upper rotating body 2 is mounted rotatably on a crawler type lower traveling body 1 and a working attachment 9 comprising a boom 3, an arm 4, a bucket 5 and hydraulic cylinders (boom cylinder, arm cylinder, bucket cylinder) 6 to 8 for actuating those boom, arm and bucket respectively are attached to the upper rotating body 2.
An engine room 13 (a tank accommodating space recited in claim 1), which is enclosed with right and left side panels (only one-side panel is shown) 11 and a bonnet 12, is provided at a rear portion of an upper frame 10 constituting the upper rotating body 2. A fuel tank 14 is accommodated within the engine room 13 together with devices, including an engine (not shown).
The bonnet 12 is formed in L shape which covers both upper surface side and rear surface side of the engine room 13. The bonnet 12 is secured to the upper frame 10 through a support member (not shown) in a state in which it turns on a bonnet shaft (hinge) 15 disposed at a front end portion of the bonnet to open and close both upper and rear surface opening portions.
FIG. 6 shows a state with the bonnet 12 closed, while FIG. 7 shows a state with the bonnet 12 opened. Maintenance of the devices is conducted in an opened state of the bonnet.
An operator's seat 16 and operating levers (only one is shown in FIG. 6) 17 are installed on the bonnet 12 and an operator O operates the levers while sitting on the operator's seat 16 as shown in FIG. 6.
In the drawings, the numeral 18 denotes a rear frame provided at a rear end of the upper frame and serving also as a counterweight.
In this conventional compact excavator, the fuel tank 14 is secured to the upper frame 10 through brackets by fastening means at a plurality of positions in the vertical direction such as, for example, upper and intermediate positions (see Japanese Utility Model Laid-Open Publication No. Hei 2 (1990)-148831).
However, according to the related art wherein the fuel tank 14 is fixed with only the fixing force of fastening means, it is necessary to fix the tank at plural positions and a bracket is needed at each fixing portion. As a result, not only the tank mounting structure becomes complicated, but also the tank mounting work is troublesome.
According to the related art, moreover, the tank fixing portions are specified, so particularly in the case of a plastic fuel tank, the tank mounting work becomes more troublesome due to dimensional variations and deformations. Further, there also has been the problem that the fastening means are apt to become loose.